This invention relates to electrochemical heating devices and more particularly to a strong, compact, conformable, self-contained, non-toxic and flameless heating source for use in heating military field rations, as heating pads, as medical hot compresses and body warmers.
Several prior art heating sources having somewhat flexible construction have been proposed. The U.S. Pat. Nos. 3,774,589 to Kober, and 3,942,511 to Black, et al, show heat cell structures which are fabricated from separate components and then assembled. However, the integrity of these structures is destroyed if the constructions are damaged by improper handling or if cut, and their manufacture is expensive. Also, U.S. Pat. Nos. 4,080,953 to Mitchell, 3,980,070 to Krupa, and 3,874,504 to Veraks, provide limited flexibility from loose powdered material which requires a pouch or other container to hold the reactants and concentrate the heat. The sandwich structure in Black, et al, U.S. Pat. No. 3,942,511, while providing flexibility is complicated, less efficient and difficult to manufacture. These and other prior art devices lack ease in manufacture, material strength or flexibility to conform to any surface.